Skip to main content

Table 1 Potential impact of hydric stress on female survival and infection prevalence during 7-day stress period

From: Hydric stress-dependent effects of Plasmodium falciparum infection on the survival of wild-caught Anopheles gambiae female mosquitoes

Potential impact of hydric stress

Predicted measured effects

Hypothesis

Direct negative

effect on survival

Increased parasite-induced

mortality

Female

survival

Infection

prevalence

1

No

No

none

none

2

Yes

No

decreased

none

3

No

In early stages of infection (days 0-4)

decreased(days 0-4)

decreased

4

Yes

In early stages of infection (days 0-4)

decreased(days 0-7)

decreased

5

No

In late stages of infection (days 4-7)

decreased(days 4-7)

none

6

Yes

In late stages of infection (days 4-7)

decreased(days 4-7)

none

  1. Mortality incurred through the direct effect of hydric stress is distinguished from that due to increased parasite-induced mortality in females under stress. The occurrence of one or both of these sources of mortality and their timing leads to several possible hypotheses (1-6), each yielding distinct predicted patterns of measured female survival and overall oocyst prevalence. Because ookinetes and very young oocysts in early-dying females (days 0-4) are undetectable, an increase in parasite-induced female mortality in response to hydric stress at that stage translates in an apparent decrease in the prevalence of oocysts detected in females dying later in that experimental group (hypothesis 3 - in bold).